Shindoi José María, Matsumoto Yoshiro, Sato Yutaka, Ono Takashi, Harada Kiyoshi
Department of Maxillofacial/Neck Reconstruction, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan.
J Oral Maxillofac Surg. 2013 Jan;71(1):e24-30. doi: 10.1016/j.joms.2012.08.015. Epub 2012 Oct 23.
Proportionality of the lower and middle thirds of the face is a key determinant of successful orthognathic treatment. A flatter profile and marked variance of the soft tissue envelope in the Japanese population complicates the accurate assessment of these proportions. This study aimed to identify gender differences and establish norms for Japanese young adults using the method of soft tissue cephalometric analysis (STCA) by Arnett et al (Am J Orthod Dentofacial Orthop 116:239, 1999).
Lateral cephalograms of 49 young normal Japanese subjects (19 men, 30 women) were selected from the archival records and analyzed with STCA. The Student t test was used to compare mean values of the male and female groups.
Significant differences were found between women and men. Men had a flatter occlusal plane and a more acute nasolabial angle than women. Men showed larger values for upper and lower lip thickness, menton soft tissue thickness, and vertical face length, especially in the lower third of the face. Women had a more projected midface than men. Compared with established STCA norms, the Japanese have more midfacial projection.
Significant gender differences were found in the thickness, lower third length, and midface projection in Japanese young adults, which should be taken into account when interpreting measurements for orthognathic surgical planning. These differences can serve as norms for STCA in young Japanese adults. Differences were noted between the reference values of Arnett et al and Japanese subjects.
面部下三分之一与中三分之一的比例关系是正颌治疗成功的关键决定因素。日本人群面部轮廓较平且软组织覆盖存在明显差异，这使得准确评估这些比例变得复杂。本研究旨在利用Arnett等人（《美国正畸与牙颌面正畸杂志》116:239, 1999）的软组织头影测量分析（STCA）方法，确定日本年轻成年人的性别差异并建立相应标准。
从存档记录中选取49名正常日本年轻受试者（19名男性，30名女性）的侧位头影测量片，并用STCA进行分析。采用学生t检验比较男性和女性组的均值。
发现女性和男性之间存在显著差异。男性的咬合平面较平，鼻唇角比女性更锐。男性的上、下唇厚度、颏部软组织厚度和垂直面高度值更大，尤其是面部下三分之一部分。女性的中面部比男性更突出。与既定的STCA标准相比，日本人的中面部更突出。
在日本年轻成年人中，发现厚度、面部下三分之一长度和中面部突出度方面存在显著的性别差异，在解释正颌手术规划测量结果时应予以考虑。这些差异可作为日本年轻成年人STCA的标准。还注意到Arnett等人的参考值与日本受试者之间存在差异。
